Method of depositing copper and other metals.



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ALFRED SANG, 0]?

METHOD OF DEPOSITING Specification of Letters Patent.

No Bra wing.

SE'JVICKLEY, PEIINSYLVANIA.

corrnn AND o'rHEn METALS.

To all whom it may concern:

Be it known that I, ALFRED SANG, of Sewickley, Allegheny county, Pennsylvania, have invented a new and useful Method of Depositing Copper and other Metals, of which the following is a act description.

This invention has reference to a novel method of depositing copper, or copper and another metal, such as zinc, upon iron and steel to form a protective coating therefor, and provides a simple and effective way of forming upon iron and steel articles a surface coating composed either of metallic copper alone, orof successive layers of copper and another metal, such as zinc, or of an alloy of copper and another metal such as zinc.

In carrying out my invention, the articles to be coated are first thoroughly cleaned by any well known method, such as pickling or sand-blasting, or by the combined steps of pickling and sand-blasting. They are then placed in a closed, vessel and-are packed or covered with metallic copper in the form of a very fine dust or powder, or with a mixture of copper dust and another metal, such as zinc dust, depending upon the character of the coating which is to be formed.' The receptacle is then subjected to heat substantially as in the sherardizing process, exept that a somewhat higher temperature (preferably about 1000 degrees F.), should be employed when copper alone is used, or when a considerable percentage of copper is employed.

When the articles are removed from the receptacle, after it has been allowed to cool, if copper alone has been used as the covering or packing material, they are found to have on their surfaces a' smooth, uniform, and closely adherent coating of copper, 'of a thickness depending upon the length of time occupied in the treatment. When a mixture of copper and zinc dust is employed, the articles will be found to have a double-layer coating, the inner layer being copper and the outer layer of zinc, with the two layers more or less alloyed where they join each other. The surface layer of the coating may .be thick enough so that the articles will present substantially t e same appearance as sherfull, clear, and exduring are alloyed. 13y: properly regulating the proportions of zinc and copper dust, the coating may be made to consist substantially wholly of an alloy of the two metals. found that five per cent. (by weight) of copper dust, or even less, 4 will give a plainly perceptible coppery appearance to the coating. i

Carbon may or may not be used in the receptacle .during the operation. \Vhen used it need not be in powdered form but may be either powdered or in lumps, the latter being preferred. 4

The copper used should be in the form of a-very fine powder or dust. I preferably obtainthis dust by precipitating the copper from a solution of its sulfate by means 0 zinc dust. I use a cold copper sulfate solution, adding the zinc dust slowly, and with agitation, which gives a precipitate in a very fine form. I preferably subject the receptacle containing the articles to be coated and the material 1n which they are packed to agitation the time the receptacle is being heated. Instead of mixing zinc. dust with the cop er, I may use someother metal instead o zinc dust. -'I have also found that by using a graphite or clay, or clay-lined receptacle, much better and quicker results are obtained, with less loss ofcoating metals. The coating produced superior to that produced by method with which I am familiar; since copper is harder and more resistant than zinc, and affords a better protection against oxidation, especially when exposed to seawater; When the coating consists of a compound layer of copper and zinc, it has peculia-rly resistant properties, due in part to. the double coating as such, and in part to the, interposition of the copper between the iron and steel and the zinc, whereby there is a less abrupt difference in the electrochemical propertles of the iron and steel and of the outer zinc coating. What I claim is 1. The method of depositing copper on iron and steel surfaces, which comprises applying metallic copper in powdered form to the surface to be coated and in subjecting the same to heat; substantially as descrlbed.

,2. The method of depositing copper and another metal on iron and steel surfaces, which comprises applying to the surface to be coated a mixture of the copper and other by my invention is 4 any other" Patented Feb. 8, 1910. Application filed March 25, 1908. Serial No. 423,122.

I have mixed with zinc dust,

zinc dust, an "substantially zinc on iron and steel, which comprlses surrounding the articles to be coated with a mixture of owdered metallic copper and d in subjecting the same to heat;

as described. 4. The method of applying a coating of copper and zinc in successive layers, on the sur aces of iron or steel articles, which comprises bringing the articles into contact with a mixture of powdered zinc and co per, and subjecting them to heat; substantia ly as described. 5. The method of applying a coating of cop er-zinc allo t0 the surfaces of iron and stee articles, wll articles into contact with a mlxture of powdered zinc and copper, with the zinc in excess of the copper, and subjecting the same to heat; substantiall as described.

6. The method of depositing copper and another metal on iron and steel surfaces,

and in subjectin -metal in powdered form,

ich comprises bringing the ceases which comprises applying to the surface to be coated a mixture of copper and other together with car bon, and in sub'ecting the same to heat; substantially as described; 7. The method of depositing copper and o zinc on iron and steel, which comprises surrounding the articles to be coated with a mixture of powdered metallic copper and zinc dust, together with carbon, and in subjectin the same to heat; substantially as descri ed.

8. The method of depositing copper and zinc on iron and steel, which comprises surrounding the articles to be coated with a mixture of powdered metallic copper and 40 zinc dust, and in subjecting the same to heat and agitation; substantially as described.

In testimony whereof, I have hereunto set M my hand.

' ALFRED SANG. Witnesses:

W. G. WINTERHALTER, F. O. HoomNsoN. 

